The present invention relates to the field of downhole drilling for oil, gas, and geothermal exploration. With a continually increasing demand for downhole drilling, the ability to drill more effectively through the use of electronics in a drill string has become more popular. Such electronics may be used to determine the direction of drilling, monitor the condition of the drilling equipment, determine subsurface formation parameters, and so forth. In order for the electronics to work they must have power. The present invention provides a method, apparatus and system for generating power downhole.
U.S. Pat. No. 6,191,561 which is herein incorporated by reference for all that it contains, discloses an apparatus for generating and regulating power downhole by varying the alignment of a pair of axially adjacent permanent magnets attached to a drive shaft which rotates within an armature having electrically conductive windings. In the current invention the shaft of the generator is preferably connected to a mud turbine engine.
U.S. Pat. No. 5,965,964 which is herein incorporated by reference for all that it contains, discloses a generator having a sleeve slidably disposed within a housing which oscillates in response to the application of fluid pressure to the current generator. A piston is slidably attached to the sleeve and oscillates relative to the sleeve and the housing. The piston extends longitudinally into a generator section and has a plurality of magnets attached thereto which oscillate with the piston. Wire coil sections are fixed relative to the housing of the generator section and are positioned between the oscillating magnets such that a current is induced in the wire coil sections upon oscillation of the magnets.
U.S. Pat. No. 6,691,802 which is herein incorporated by reference for all that it contains, discloses a drill string equipped with a downhole assembly having an instrumented sub and a drill bit. The instrumented sub has a power source that requires no electrical chemical batter. A mass-spring system is used, which during drilling causes a magnet to oscillate past a coil. This induces current which is used to power downhole instruments.
U.S. Pat. No. 6,504,258 which is herein incorporated by reference for all that is contains, discloses a downhole power generator that produces electrical power for use by downhole tools. In a described embodiment, a downhole power generator includes a member that is vibrated in response to fluid flow through a housing. Vibration of the member causes a power generating assembly to generate electrical power.